The present invention relates to the technical field of transporting and separating fibrous materials used for insulation such as mineral wool, fiberglass and cellulose materials. More particularly, the present invention is directed to an apparatus for separating fibrous material which is suspended and being transported by air.
Fibrous materials including mineral wool, fiberglass and cellulose are today commonly used for insulating buildings and homes. The fibrous material is typically conveyed and applied in attics and walls through hoses wherein air travels at a sufficiently high velocity to carry the fibrous material through the hose and to the location being insulated. Essentially, the fibrous material is mixed in or otherwise introduced into the high velocity air traveling through a hose thereby carrying the fibrous material through the hose and to the location being insulated.
When filling vertical stud wall cavities, the conveyed fibrous materials are typically admixed with water and adhesives for creating a solid layer of insulation which is then sprayed between the vertical studs. The resulting rough surface is typically leveled to the stud face and the excess removed material falls to the floor wherefrom it is recovered and reused. It is most efficient to recover the excess fallen fibrous material by vacuum or pressure pneumatic systems and to convey the material directly back to the insulation application machine whereat the recovered fibrous material insulation is typically blended with new insulation.
Prior to reintroducing the recovered fibrous insulation into the insulation application machine, the recovered fibrous insulation must be separated from the air in which it was suspended. Essentially, the fibrous material must be separated from the air stream. Although separators and/or filters have previously been devised for this purpose, they are not without substantial shortcomings and drawbacks. For example, Kopena, U.S. Pat. No. 4,447,249, utilizes a rotating screen that progressively moves the collected material from a high to a low pressure zone for removing the fibrous material from the air stream. However, the rotating screen can not remove all of the fines and additional filtering is required downstream.
Roe, U.S. Pat. No. 5,934,476, utilizes a rotating screen with a plurality of cavities for separating the fibrous materials. Similarly, however, downstream additional filtering is required for removing the finer fibrous materials.
Stamatiou et al., U.S. Pat. No. 4,128,404, describes a cyclone separator having an internal perforated conical screen. Fibrous materials trapped by the screen are cleaned therefrom with rotating air nozzles or wiper blades in sliding contact with the screen. Again, the separator does not remove the finer fibrous particles and additional separation and filtering is required downstream.
Accordingly, a need exists for a separator capable of separating fibrous materials being carried by and suspended in air effectively and efficiently, and also removing substantially most of the finer fibrous particles thereby generally eliminating the need for additional downstream filtering.
It is the principal object of the present invention to overcome the above-discussed disadvantages associated with prior fibrous material separators.
It is an object of this invention to provide a compact, efficient method and apparatus for removing fibrous materials such as wool, paper, insulation, synthetic fibers from vacuum or pressure pneumatic conveying systems without the need for additional downstream conveying filtration.
It is a further object of this invention that part of the material being conveyed be continually retained and utilized as a highly efficient filtering media for the conveying air or gases.
It is a further object of this invention to provide an adjustable rotating screeding device to control the thickness of the retained fibrous media that serves as a filter.
It is a further object of this invention to provide an automatic device to control the thickness of the retained fibrous media.
The present invention overcomes the disadvantages associated with prior separators by providing a housing having an inlet for receiving the air and the fibrous material suspended therein, an air outlet and a fibers outlet. A screen is provided at the housing air outlet for allowing air to pass but generally restricting the fibrous material from exiting therethrough. The air and fibrous material entering the housing inlet are at a higher pressure than the air outlet thereby causing the air to flow therethrough, and also thereby accumulating fibrous material on the screen as the air passes therethrough. The housing preferably includes a cylindrical wall portion and rotating vanes therein located between the housing inlet and the fibers outlet. The rotating vanes have peripheral edges traveling adjacent the housing inner cylindrical wall thereby generally restricting air flow from the housing inlet to the fibers outlet. Therefore, substantially all the air is forced to exit the housing through the screen.
A scalping blade is provided which is adapted to travel over and at a desired distance from the screen. As air exits through the air outlet and fibrous material accumulates on the screen, the fibrous material which accumulates beyond the desired distance from the screen is removed therefrom by the scalping blade and falls by gravity through the fibers exit. However, fibrous material accumulated on the screen between the scalping blade and the screen, remains on the screen thereby forming a fibrous filter mat whereby smaller fibrous material and particles are effectively filtered and separated from the air exiting through the air outlet.
Preferably, the air outlet and screen are located at one longitudinal end of a housing cylindrical wall and the scalping blade extends radially from a rotating shaft extending longitudinally therein. Yet more preferably, a pressure differential transducer is provided for comparing the pressures in the housing and at the air outlet and selectively energizing an actuator for moving the screen and decreasing the distance between the screen and scalping blade in response to increasing pressure differential and, for increasing the distance between the screen and scalping blade in response to decreasing pressure differential.
The air is conveyed through the housing inlet and out through the air outlet preferably by either connecting a vacuum hose to the inlet and connecting the air outlet to a vacuum pump or, in the alternative, connecting the housing inlet directly to a pneumatic pressure conveying system.
In one form thereof, the present invention is directed to an apparatus for separating fibrous material suspended in air. The apparatus includes a housing having an inlet for receiving the air and fibrous material suspended therein, an air outlet, and a fibers outlet. A screen is provided at the housing air outlet for allowing air to pass but generally restricting the fibrous material from exiting therethrough. The air and fibrous material entering the inlet are at a higher pressure than the air outlet thereby accumulating fibrous material on the screen as air passes therethrough. Rotating vanes are provided in the housing between the inlet and the fibers outlet generally restricting air from exiting through the fibers outlet. A scalping blade is adapted to travel over and at a distance from the screen. Fibrous material accumulated on the screen beyond that distance is removed from the screen by the scalping blade and fall through the fibers exit. The fibrous material between the scalping blade and the screen remains on the screen thereby forming a fibrous filter mat whereby smaller fibrous material can be filtered and separated from the air.
In one form thereof, the present invention is directed to an apparatus for separating fibrous material suspended in air. The apparatus includes a housing having an inlet for receiving the air and fibrous material, an air outlet, and a fibers outlet. A screen is provided at the housing air outlet for allowing air to pass, but generally restricting fibrous material from exiting therethrough. The air and fibrous material entering the inlet are at a higher pressure than the air outlet thereby accumulating fibrous material on the screen as air passes therethrough. A scalping blade is provided and is adapted to travel over and at a distance from the screen. Fibrous material accumulated on the screen beyond that distance is removed from the screen by the scalping blade, and fibrous material between the scalping blade and the screen remains on the screen forming a fibrous filter mat whereby smaller fibrous material can be filtered and accumulated. An air lock is provided at the fibers outlet allowing fibrous material to exit but generally restricting air from exiting therethrough.